Plant mortality is greatest at the seed to seedling stage. Every seed is truly a structure that protects and moisturizes the baby embryo or plant, plus a certain quantity of food to tide it over the first stages of germination and growth. The moment a seed is wakened out of its suspended animation and starts to grow it will become vulnerable, not just to insects, bird, and animal life, but to states within its environment.
Germination and Growth
Although the hereditary qualities of the plant have been already fixed in the seed, health, vigor, and therefore are greatly influenced by its germination and growth from seed to seedling. The stronger, thriving, and successful plants come from seeds that germinate quickly and grow without check. The gardener’s job at sowing time is to establish those most conducive to prepared germination.
The vast majority of actively growing plants comprise about 90 percent of the weight in water. Seeds contain only about 10 percent of the weight in water. Moisture is therefore an essential to germination, to forward the necessary biochemical changes which can only proceed in solution. The rate with which seeds germinate is greatly affected by the moisture content of the soil.
Sown in dry soil, in dry weather, they may lie dormant for many days. Each seed coating is providentially pierced with a small hole admitting oxygen and moisture. Without oxygen seeds don’t germinate, for the gasoline is essential to the chemical reaction that liberate the energy for growth. Weed seedsburied in the soil, germinate when brought into aerated surfaces, to frighten and baffle the gardener, especially when they are weeds he’s rarely seen in his backyard before.
The third essential for seed germination is heat. Seeds sown in a moist soil at low temperatures are liable to rust. Seeds in themselves, while dormant, can withstand incredible variations in temperature. Dry seeds are proven to withstand the temperature of boiling water without harm, and many different seeds are stored at a temperature of 300 to 450 degrees Fahrenheit of frost, or immersed in liquid air, without injury to their germination powers.
The speed of biochemical activity involved in germination is, however, greatly accelerated when seeds are sown in heat. It’s when the embryo starts to stir that it develops its best susceptibility, the susceptibility of the plant, to fever. Seeds sown out of doors early in February or March frequently show little advantage over those sown a fortnight or more afterwards. Speed in germination is retarded, and there is very little benefit in sowing early.
Germination rate, not the sowing season or time, determines the maturity date. The better beginning the seed leaves, the nicer plant it may become. Sowing time is more appropriately gauged from the weather than by the calendar or the gardening manual. Rising temperatures arrive later, and leave earlier; the closer we get to the poles or to the skies. The opportunity to sow a certain kind of seed is largely associated with its ancestry and native location.
Runner beans hail from Mexico. In temperate zones, therefore, they have to be sown late in spring, after the threat of frost is largely removed. In germinating flower, shrub, and tree seeds even larger consideration of the native habitat of plants have to be given. Experiment and experience must guide the gardener in several instances. Therein lies much of the interest of his craft.
The tilth of this in which they’re sown largely impacts the seeds’ ability to absorb moisture. The finer the seed that the more powder-like if the seedbed be. A seedbed should be dug and permitted to settle and consolidate at least thirty days prior to sowing. Winter weathering provides a surface dirt that can be quickly worked and raked into a smooth bed.
Type of Seeds
Seeds sown in newly turned soil are apt to be washed down under germination thickness together with the particles of dirt as the ground settles. They need to also face the competition of weeds brought to the surface by digging, and germinating alongside. The thickness at which seeds are sow impacts their access to oxygen in addition to moisture. A solid rule is to sow in a depth twice their diameter.
Bigger seeds, for example Pea and Beans, with tough, tough seed coats, can withstand more depth than fine soft-shelled seeds, such as parsnips. Firming presses seeds into contact with the soil particles, but shouldn’t be overdone. The power and force a seed must use in seeking the light has much to do with its success in germination and development as a plant.
Fine soil sifted over seeds will flake and cake, and has to be pushed back by the appearing first leaves. A sifting of coarse-grained sand is not as taxing and leads to a larger percentage of germination. Soil texture has a bearing on the pore area which affects a soil’s moisture content and aeration. Better germination is possible at slightly greater depths in light sandy soils, and in a slightly less depths in clay, but the variants are just fractions of an inch.
Period of Dormancy
The period of dormancy in seeds varies considerably. Some loose their viability, capacity to resume action, quickly. Lotus seeds are germinated which were proven to be at least 150 years old, but under normal conditions the seeds of the Japanese willow, if not sown, perish within a week. Gardeners are often warned against planting parsnip seeds over 18 months old.
A wide line can be drawn between the seeds which have soft seed coatings and those that are hard shelled, the latter keeping their germinating powers for a larger period. For the part, fresh seeds germinate more readily and produce more vigorous and finer plants compared to old seeds. When seeds are sown indoors, under glass, or in greenhouses, temperature, moisture, and other variables are more strictly under our direct control.
As seeds need no food until they get to the infant plant stage, they may be germinated in moist sand, sphagnum moss, poor soil, or even peat, just, but a more satisfactory control on moisture and aeration in afforded by building a seed compost. As it is hard to draw a line between the fatigue of a seed’s own food reserves and its subsequent dependence on its surroundings, it’s also smart to make up seed composts adequate rich and suitable for sustaining unbroken action and growth.
The first phases of vegetation are so crucial to the future growth it is surprising that the basic operation of preparing seed and seedling compost received little critical scientific focus.
You can find a searchable compost of great texture for overall seed sowing indoors. The addition of phosphates in seed composts is valuable since phosphorus is particularly necessary for leaf and root growth in the seedling stages. A light dressing of the seedbed with superphosphate always pays dividends in sturdier seedlings, equipped with larger leaves, and much more actively foraging roots.